Method for balancing color wheel and structure therof

ABSTRACT

A method for balancing a color wheel comprising: step (a), measuring the rotational deviation vector of a driving motor, including its deviation amount and direction; step (b), adjusting the deviation of a color wheel to make its deviation amount to be the same of the driving motor; and step (c), connecting the color wheel to the driving motor and let the deviation direction thereof to be opposite to each other to reach an expected balance. According to the present invention, an embodiment of the color wheel structure may includes a set of color filter and a ring, before to start the assembly, adjusting the deviation vector of the ring and motor shaft first, and then to assemble it and make the deviation vectors oppositely.

FIELD OF THE INVENTION

The present invention relates to an assembly method for color wheel andthe structure; and, more specifically, to a method comprising a step ofmeasuring the rotational deviating vectors of a motor and a color wheel,and assembling them in opposite deviation direction.

BACKGROUND OF THE INVENTION

Digital Light Processing (DLP) has been well developed and applied indigital projector. Recently, the digital projector has shown a highpotential to share traditional liquid crystal projector market;meanwhile, the key element, so-called color wheel for carrying a set ofcolor filters has played an important role in determining the quality ofthe projector. For instance, while the color wheel rotates in anextremely high speed, any rotational unbalance once occurred shallgenerate a high frequency noise, thus would damage the manufacturer'sgoodwill directly while in operation in meeting. Therefore, how toimprove the rotational balance of the color wheel in a better assemblyprocess would be highly emphasized in the art; even if there is only asmall breakthrough in structure or method, would be helpful for thecompany's potential in market competition and reputation, allowing nodefect therein.

For structural concepts, design limitations and material choice tomanufacture a color wheel, the readers may referring to U.S. Pat. No.5,868,482 and 6,024,453; therefore we should not to repeat all the stuffagain and again. However, the present invention would focus on how toassemble a color wheel to get a perfect rotational balance, which hasnot taught in the related patents.

Currently, there are two major traditional methods for balancing a colorwheel. Referring to FIG. 1, the first method is to bond a weight (22) tothe ring (21) after the color wheel connected to driving motor (10).Referring to FIG. 2, the second method is to remove weight by forming arecess (23) on the ring (21). For the first method, due to the weight(22) has protruded from the surface which may arise unexpected noise bywind cut. For the second method, we found that it is difficult toprecisely remove the weight to reach a perfect rotational balance on thering (21).

As shown in FIG. 3, the invention disclosed in U.S. Patent PublicationNo. 2003/0035218 A1, having a ring (21) of color filter (20) with anannular groove (24) on the face which is opposite to the side of motor(10). The function of the annular groove (24) is use to add weight (25)to reach a rotational balance.

There are several factors could led to rotational unbalance of colorwheel; for instance, most of the shaft (31) of the driving motor arenaturally unbalanced in rotation, or the color filter which may also notbe bonded on perfect position, or the thickness of adhesive layer mayunevenly formed under the color filters. This and these are all variablefactors to the quality of color wheel. Therefore, the known methods forbalancing a color wheel, is to adjust the balance after the color wheelis assembled with driving motor. As shown in FIG. 1 to FIG. 3, theappearance of the color wheels are easy to appear defects. For moreworse case, a wind cut noise may then be generated.

SUMMARY OF THE INVENTION

It is one object of the present invention to provide a method for colorwheel assembly, included to measure and adjust the deviations of thecolor wheel and the motor before the assembly.

In accordance with the present invention, the method may comprising thesteps of: (a), measuring the rotational deviation vector from a drivingmotor, including its deviation amount and direction; (b), adjusting thedeviation of a color wheel to make its deviation amount be the same ofthe driving motor; and (c), connecting the color wheel to the drivingmotor and let the deviation direction thereof be opposite to each otherto reach an expected balance. According to the present invention, anembodiment of the color wheel structure may includes a set of colorfilters and a ring, before to start the assembly, adjusting thedeviation vector of the ring and motor shaft first, and then to assembleit and make the direction of deviation vectors oppositely.

DESCRIPTION OF THE DRAWINGS

The above description or other characteristics, objects, features andadvantages of the present invention will become more apparent uponconsideration of the following detailed description, having reference tothe accompanying drawings wherein;

FIG. 1 is a cross-sectional view illustrating an existing color wheelinstalled with a motor;

FIG. 2 is a cross-sectional view illustrating another existing colorwheel installed with a motor;

FIG. 3 is a perspective view illustrating another existing color wheelinstalled with a motor;

FIG. 4 is a block diagram showing the steps for balancing the colorwheel in accordance with the present invention; and

FIG. 5 illustration the structure of the color wheel in accordance withthe present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

As shown in FIG. 4 and FIG. 5, an embodiment of color wheel inaccordance with the present invention, may comprise a ring (40) and aset of color filter (41). Preferably, to create an annular grove (42) onthe ring (40) has. To compare with the annular groove (24) of FIG. 3 asthe same disclosed in U.S. patent publication No. 2003/0035218 A1, theannular grove (24) on the ring (21) of the prior art is formed on theopposite side to the driving motor (10), and that would appeared on theoutward appearance of the product. However, the annular grove (42) ofthe present embodiment would be hide when been assembled with a drivingmotor (30).

Referring again to FIG. 4. The method in accordance with the presentinvention, may including: step (a), measuring the rotational deviationvector (F1) from a driving motor (30), included the deviation amount anddirection thereof, preferably; to apply a mark on the shaft (31) of themotor (30) to indicate the direction of rotational deviation vector(F1); step (b), adjusting the rotational deviation vector (F2) of thecolor wheel by adding adhesive (43) into the annual groove (42), and toadjust the deviation amount of the rotational deviation vector (F2), andmake the deviation amount to be the same of rotational deviation vector(F1); and step (c), connecting the color wheel to the driving motor (30)and make the direction of rotational deviation vector (F1) and (F2) becomplete opposite to each other to reach an expected balance. Therefore,the rotational deviation vector (F1) can be balanced by the rotationaldeviation vector (F2), so as to reach a perfect rotational balance.

According to the present invention, the ring (40) may made of metal. Forinstance, the ring (40) is made of copper, having one surface forbonding the color filter (41) with an adhesive. To prevent the problemof adhesive overflow, it may also refer to U.S. Pat. No. 6,618,214, thering (40) may using a plurality of concentric grooves on the bondingsurface to absorb excessive adhesive and then to lead them to distributeevenly. Other solutions, may also can refer to U.S. Pat. No. 6,598,977,wherein the inventors suggested to create a gap on its ring for applyingand absorbing adhesive at a bonding surface of the ring.

To step (b), an alternative for adjusting the rotational deviatingvector (F2) on the color wheel, may also can refer to U.S. Pat. No.6,705,733, wherein the ring having a recess on the peripheral for addinga weight to adjust the rotational deviating vector of color wheel afterthe assembly of color wheel is completed. Similarly, the ring (40) ofthe present embodiment can having a recess on the peripheral foradjusting the deviating amount of rotational deviating vector (F2).Certainly, for adjusting the rotational deviating vector (F2), anotheralternative is to remove material form the ring (40), which would havethe same effect to complete the step (b).

This description is intended to provide specific examples of individualembodiments which clearly disclose the present invention. Accordingly,the invention is not limited to these embodiments or to the use ofelements having the specific configurations and shapes as presentedherein. All alternative modifications and variations of the presentinvention which fall within the spirit and broad scope of the appendedclaims are included.

1. A method for balancing color wheel comprising the steps of: measuringa rotational deviation vector of a driving motor, including thedeviation amount and direction thereof; adjusting a deviation amount ofa color wheel and to make the deviation amount be the same of thedriving motor; and connecting the color wheel to the driving motor andto let the deviation direction thereof be opposite to each other toreach an expected balance.
 2. The method in accordance with claim 1,wherein the step for adjusting the deviation of the color wheel includea step to add a weight on the color wheel.
 3. The method in accordancewith claim 2, wherein the step for adjusting the deviation of the colorwheel include a step to add an adhesive material as a weight.
 4. Themethod in accordance with claim 2, wherein the step for adjusting thedeviation of the color wheel include a step to add a balancing object.5. The method in accordance with claim 1, wherein the step for adjustingthe deviation of the color wheel include removing weight from the colorwheel.
 6. The method in accordance with claim 1, wherein the step foradjusting the deviation of the color wheel include fixing a color filterby a ring.
 7. The method in accordance with claim 6, wherein the ringhas a groove for adding a weight.
 8. The method in accordance with claim7, wherein the groove is created on the side near to the driving motorwhen an assembly thereof is completed.
 9. The method in accordance withclaim 6, wherein the groove is created on the ring at the same side ofbonding a color filter.
 10. A color wheel, comprising: a driving motorhaving a shaft with a rotational deviating vector; and a ring, connectedto the shaft of the driving motor and bonded a set of color filtersthereon, wherein the ring has a groove for adding weight to adjust arotational deviating vector thereof to be the same in deviating amountas that of the driving motor, and makes both of the rotational deviatingvectors be opposite in direction to each other.
 11. The color wheel inaccordance with claim 10 further includes an adhesive layer between thering and the color filter.
 12. The color wheel in accordance with claim10 wherein the ring is a product of metallic material.
 13. The colorwheel in accordance with claim 10 wherein the weight is a dried adhesivematerial with certain weight.
 14. The color wheel in accordance withclaim 10 wherein the weight is a solid material with certain weight. 15.A color wheel, comprising: a driving motor, having a shaft with arotational deviating vector, wherein the rotational deviating vectorincluded a deviating amount and a deviating direction; and a ringconnected to the shaft of the driving motor and bonded a set of colorfilters, wherein the ring having a surface near the driving motor forremoving weight and forming a recess for adjusting the rotationaldeviating vector, and make the rotational deviating vector with a samedeviating amount of the driving motor, and in opposite deviatingdirection to the driving motor.
 16. The color wheel in accordance withclaim 15 wherein the set of color filters is bonded to the ring by alayer of adhesive.
 17. The color wheel in accordance with claim 15wherein the ring is a metallic ring with a central hole for engagingwith the shaft of the driving motor.